Two labourers were killed while three were injured as a pillar of an under-construction flyover in Islamabad’s Bhara Kahu collapsed on Saturday, Islamabad police said.

According to a tweet by the police, two labourers were taken to the Pakistan Institute of Medical Sciences, where one succumbed to injuries. Three other labourers were taken to Polyclinic Hospital where one could not survive as well.

It added that senior officials of the police and administration — including Islamabad Inspector General (IG) Dr Akbar Nasir and Chief Commissioner Noorul Amin Mengal — were present at the incident site.

In a separate tweet, it said a committee, which will be headed by Islamabad Deputy Commissioner Irfan Nawaz Memon, has been constituted to “review all aspects related to the incident”.

Mengal, who is also the Capital Development Authority (CDA) chairman, said that according to the preliminary investigation, “two to three huge trolleys (trucks) had passed by the bridge between 2-3am and had hit it”.

He added that both “safety and traffic protocols” had been violated and a committee had been formed to find out “who was responsible so they could take legal action against them”.

The CDA official said further details will be revealed once the committee finds them out.

Talking about the Bhara Kahu bypass project, he termed it a “very complicated project” as it was a “challenge to close the one-link” that leads to the northern areas.

Saying that the project had entered a “critical stage”, Mengal said heavy traffic needed to be shut down. Mentioning construction work still left, he said the administration would have to enforce stricter rules and “the citizens would also have to bear difficulties” for while.

Earlier in the day, the police had tweeted alerting citizens of the incident and advising them to avoid the flyover so that rescue activities were not hindered.